Endangered bears living in a national park in Abruzzo may get underpasses and even private bridges over roads after a male seeking a mate was run over on a busy motorway.

The four-year-old male had strayed from the park when it was struck by a car on the A24 motorway near L'Aquila as it searched for a partner or territory to claim, said Giuseppe Rossi, the head of the 130,00 hectare park spanning the regions of Abruzzo, Lazio and Molise.

"The bear was an Marsican brown bear of which there are only around 50 left, and four or five have been killed by trains or cars in the last 15 years," said Mr Rossi.

Mr Rossi said he had won approval from the firm managing the motorway for a bridge or tunnel for bears and was also working on a plan to dig 10 tunnels under roads inside the park, although funding was yet to be found.

"In the park the tunnels would be used by deer, wolves and wild boar as well as bears," he said.

The Marsican brown bear, which can weigh up to 440lb and reach 6ft 6 in height when standing, remains the main concern of park officials. Apart from road accidents, around 100 have been lost since 1971 to hunters and even poison left by what Rossi described as building speculators trying to drive out animals from areas of the park.